Aaron



(No Model.)

A. B. DOTY. ATTACHMENT FOR SHARPENING LAWN MOWERS. No. 606,333. Patented June 28, 1898.

AARON l3. DOTY, OF- MINNEAPOLIS, MINNESOTA, ASSIGNOR OI ONE-HALF TO CARL A. NELSON, OF SAME PLACE.

ATTACHMENT FOR SHARPENING LAWN-MOWERS.

SPECIFICATION forming part of Letters Patent No. 606,333, dated June 28, 1898.

Application filed February 12, 1898. Serial No. 670,063. (No model.)

To all whom, it may concern: I

Be itknown that I, AARON B. DOTY, a citizen of the United States of America, residing in the city of Minneapolis, in the county of Honnepin and State of Minnesota, have invented certain new and useful Improvements in Attachments for Sharpening Lawn-Mowers, of

which the following is a specification.

My inven tion relates to devices or apparatus by means of which the knives or blades of lawn-mowers and similar machines may be sharpened without the removal of the blades from the machines, and has for its special object the provision of suitable means by which a file may be held at the proper angle to the cutting edge of the blade and by which the file may be readily moved longitudinally of the blade, effecting an even filing'and sharpening thereof.

It is customary in making lawn-mowers to provide the same with curved blades, and my object is to provide a device which will at all times both hold the file at the proper angle with respect to the cutting edge of the blade and control the movement of the cuttingblade toward and away from the file-holder, so that as the file is moved longitudinally of the cutting-blade all portions thereof are suc ccssively brought into proximity to the file- 0 holder and evenly filed.

To this end my invention consists in a fileholder of the construction hereinafter described and in means in connection therewith for controlling the blade of the mower and bringing the part thereof operated upon by the file at all times to a predetermined distance from the edge of said file-holder.

The invention consists, further, in the constructions and combinations of parts herein- 0 after described, and particularly pointed out in the claims, and will be more readily understood by reference to the accompanying drawings, forming a part of this specification, in which- 4 5 Figure 1 is a perspective View of my device, the same being shown in connection with a portion of the bed-plate of a lawn-mower and alawnnn ower blade or knife. Fig. 2 is a front elevation thereof. Fig. 3 is a side view. Fig.

4 is a plan view, and Fig. 5 is a detail view of a portion of a file having thereon a device which I employ to keep the blade of the mower from moving away from the file-holder.

As shown in the drawings, 2 represents a portion of the'bed-plate of the mower, which is secured in the lawn-mower frame in the ordinary or in any preferred'mauner.

3 represents the bed-knife, which is riveted or secured by screws to the bed-plate 2.

4 represents the main frame of my file- 6o holder. It may be of any preferred form of construction and of any desired material and has the lip or flange 5, in the groove or guideway 5 of which the bed-knife 3 slides as the holder is operated longitudinally of the knife 3, as hereinafter described. A guide-frame 6 is pivoted in the frame 5 by means of setscrews 8, the frame at being provided with screw-threaded openings through which the set-screws pass, and the tapered or conical 7o ends of the set-screws rest in bearings 7 in the frame 6. Each set-screw 8 is provided with a series of holes 8 about the face or circumference of its head, into which a round tool orpiece of metal may he slipped to tighten 7 5 or loosen the set-screw.

In place of using the form of set-screw shown anddescribed I may, if desired, use screws havingsquared or octagonal heads similar toordinarybolt-heads. Iprefer,how- 8o ever, the constructionshown and'desoribed. Adj ustingscrews 9 and 10,similar in construction to the screws 8, pass through threaded openings in the framed, theadjusting-screw 9 passing through the framed from the top thereof at a point substantially midway be tween the ends thereof. The screw 10 and its opening are located on the under side of the frame 6 and at one side of the same, and the screw 10 enters from the under side of 0 the frame 6. A plate 11, having a curved forward end, as shown, is fitted into the frame 5 below the pivoted frame 6. A long slot 11 is provided in said plate 11, and a set-screw 12 of the same general construction and form 5 as the set-screws Sis provided, adapted to screw into a threaded opening inv the frame 4.. A washer 12' is provided between the head of the set-screw and the plate 11. The position of the plate 11 in the frame may thus be adjusted as desired.

Near the front end of the plate 11 I provide a threaded opening 13, adapted to receive an adj listing-screw 13 for the purpose hereinafter specified.

In use the frame is placed in the frame 4 and secured therein by the set-screws 8. A file 18 is then passed through the slot in the frame 6 and the desired tilt given to the file 18 by means of the adjusting-screws 9 and 10, so that the file will have the proper lateral slant to conform to the spiral or curve of the blade to be sharpened. By tightening the respective screws 9 and all movement of the file in the frame 6 is prevented. The adjusting-screw 13 is adjusted and the frame (3 swung down, so that the file rests on the head thereof, thereby bringing the file at the same angle as the bevel of the blade to be sharpened. 14 represents the lawn-mower knife or blade, and 14 its supporting bar or rod, which is connected to the revolving frame of the lawn-mower. The file-holder is then slipped onto the bed-knife 3 of the mower, as shown in Fig. 1, the revolving knife 14 brought up against the curved end or lip of the plate 11. A retaining-collar 15, having an opening 16, is then slipped over the file (see Fig. 5) and the collar brought up toward the knife 14, so that the end orlip of the plate 11 and the collar 15 form aguide for the knife 14. The collar 15 is then fixed on the file by a set-screw 17, which passes through a threaded opening in the collar 15. The operator then takes hold of the handle portion 19 of the file-holder, passing his fingers about the file 18. With his other hand the operator grasps the other end of the file. The file and holder are then moved longitudinally of the bed-plate, and by the movement thereof the spiral knife is brought into position to be sharpened by the file, all points of the knife 14 being brought into the same proximity to the bed-plate and file-holder. The knife 14 is thus evenly and quickly filed at the same pitch throughout its entire length and is at all times entirely under the control of the operator.

It is obvious that many slight modifications of my device will readily suggest themselves to one skilled in the art, and I do not therefore wish to be confined to the exact construction shown and described.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. The combination, in a device of the class described, of a file-holder, consisting of a main frame, a pivoted frame, means for adjusting the position of a file interposed in said pivoted frame, a file, and means for bringing successively all parts of the knife or blade to be sharpened to a predetermined position with respect to the file and holder, substantially as described.

2. The combination, in a device of the class described, of a file-holder frame, a file, a pivoted frame, means for adjusting the position of the file and holding the same therein,means for limiting the downward movement of said pivoted frame and file, and means whereby all parts of the knife or blade to be sharpened are brought to a predetermined position with respect to the file and holder, substantially as described.

3. The combination, in a device of the class described, of a file-holder frame, a file, a pivoted frame, a plate 11, means for regulating the lateral pitch of said file, and means for limiting the downward swing of said pivoted frame and file, substantially as described.

4. The combination, in a device of the class described, of a frame 4, a frame 6 pivoted therein, adj Listing-screws 9 and 10 provided in said frame 6, a plate 11 adjustably secured to said frame 4, an adj Listing-screw 13 provided on said plate 11, and a file interposed in said pivoted frame, substantially as described.

5. The combination, in a device of the class described, of a file-holder frame, a pivoted frame, a file, a plate 11 adjustably secured in said frame 4, screws 9 and 10 whereby the lateral pitch of said file is regulated, an ad j usting-screw 13, a collar15 and a set-screw thereon, substantially as described.

In testimony whereof witness my hand this 22d day of January, A. D. 1898.

AARON B. DOTY.

In presence of-- FREDERICK S. LYON, R. J. BURGLEHAUS. 

